Propeller drive for outboard motors



OCL 17, 1933- L. J. JoHNsoN 1,931,075

rnorsnnnn muva Fon ou'ronn lo'rons Filed April 4, 192B Patented Oct. 17, 1933 UNITED STATES PATENT OFFICE PROPELLER DRIVE FOR OUTBOARD MOTORS larlyto a shock absorbing means arranged inthe Y driving connection between the motor and the propeller and in particular, located inthe submerged gear housing and constructed and arranged so that when the propeller strikes solid objects such as rocks, logs, snags, and the like,V

the shock absorbing mechanism will yield so as to prevent injury to the propeller. Y

Another object of my invention resides in the construction and arrangement of the shock absorbing mechanism in the form of a slip clutch located on the propeller shaft within the gear` housing which location provides a convenient and compact arrangement not only for assembly butl for constructional and repair purposes and for facility in function and operation.

Another object of my invention resides in the arrangement of this slip clutch in combination with the shear pin connecting the propeller rigidly to the propeller drive shaft and wherein the slip clutch is arranged to yield at a point ofpressure at which the shear pin will not break whereby the shear pin itself is protected and which shear pin in turn will break in case the Vslip clutch fails to function. :A

VYet another object of my invention residesin the particular details of construction of the slip clutch itself and the manner in which the spring portion thereof is housed within the portions of the clutch and about the propeller drive` shaft whereby a most compact arrangement is provided.

Still another object of my invention resides in s the details of construction of this slip clutch and particularly the manner in which lubricant within the gear housing may be fed to one end of the Cpropeller drive shaft.

These and other objects of my invention will be apparent from a perusal of the following speciflcation when taken in connection with the accompanying drawing wherein:

The single figure is a side sectional view of the preferred construction of my present invention. Referring now to the drawing in detail, in the form shown, a gear case 2 is shown as comprising a hollow casting preferably of light metal such as aluminum or aluminum alloy. It is provided in a vertical direction with a substantially central tubular bearing 4 in whichft upper and lower bearings 6 ands respectively in which the connects with shaft 14 driven from the gas engine Y `forming the prime mover of the outboard motor as `is well known in the art. The `upper portion of thehousing 12 is provided with bolt holes Ato receive the fastening bolts 1.6 and 18 adapted to connect an upper hollow casing 20 with the gear casing 2 in the manner shown in my application filed jointly with Harry L. Johnson, January 16, 1928, Serial No. 247,004. This upper section 20 is preferably provided with water conduits such as pipes 22 and 24 connecting with the water cooling" system of the engine jacket. In the preferred form of my inventionthis" upper section 20 and the lower housing 2 are adapted to be turned for steering or may be turned 180 degrees for reversely driving the boat. If desired, the housing 2 may be stationary as invsome types of outboard motors. V

The' housing 2 is provided with partitions 26 and 28 which form a lower chamber 30 adapted to contain lubricant. In, addition, the lower portion of the, housing 2 is provided with a depend'` ing projectionv or skeg 32. .The front partofthe housing `is preferably provided with an opening, the edge walls of which are formed ywiththreaded bolt holes 34 for receiving af gear case head 36.' This gear case head lis in turn provided .witha peripheral flange 38 formed with holesV and socketsv through `which bolts 40pass so as `to attach the head to the housing. This head is'fpreferably formed with hollow portions 42 for lightness and is formed centrally with'` a seat for a tubular lbearing 44' in Vwhich one end of the propeller shaft is mounted as hereinafter described. The front wall of the gear case head forms a substantially. blunt nose in conformation with the usual blunt nose of ,a streamline formation. ,The rear of the lower portion of the housing 2 is provided with rearwardly projecting walls 46` and an opening for abearing 48 in line withthe bearing 44. vThis bearing 48 receives the opposite end'of the propeller shaft`50. rectly upon the shaft 50 and is rigidly held there,

' on by means ofthe shear pin 544.v Theouter end the propeller shaft 50. The front portion of the The propeller 52 is mounted dipropeller shaft 50 is provided with aspirallyV ar-` ranged o il groove 62 and this portion of the shaft is adapted to revolve in the `bearing sleeve 44.` A threaded plug 64 Ycloses the front end ofthe gear case' head and is in line directly withithe front end of the propeller drive shaft 50. A lock nut 66 threads onto the plug 64.

member.

about the drive shaft 50.

The shock absorbing device, forming one of the important features in my presentv invention, is mounted directly within the lower portion of the propeller carrying housing 2 and concentrically about the propeller shaft 50 so that'it is whollyl enclosed in oil and may be removed from the housing 2 by removing the gear case head 36. The

shock absorbing device comprises a slip clutch.

formed of an inner clutch member 68 slidably keyed by means of a key '70 on shaft 50, sliding.

in a groove formed in the bore of the member 68. This inner clutch member'has an outer conical face 72 and is provided withV a hollow .recess '74 for housing a coil spring 76. The enlarged end of the inner member of the slip clutch is open so as to permit the insertion of the spring into its recess and this opening is closed'by a;

plug or collar 78 which may be secured directly to the drivev shaft 50` by means of diametrically disposed'pins 80. VThe outermember lof 'the slip clutch 82 likewise has a conical bore face adapted tolcontact with the face -72 of the inner clutch In addition, this outer member 82 is provided with bevel gear teeth 84 adapted to mesh With bevel gear teeth 86 on the lower end of the bevel-gear pinned as at 88 to the vertical motor driven shaft l0 and the forward end of the outer member 82 of the slip clutch is providedwith threads 90 upon which screws a collar or cap 92 having an inwardly extending flange engaging` over the front face of plug 78 and fitting somewhat closely about the drive shaft of the propeller shaft 50 so asl to forma complete housing for the inner member '72 of the slip clutch. The rear face ofthe bearing 44'is provided with an oil duct 94 whereby oil may be fed'tov the vspiral duct 62.

If the propellertshould strike a snag or solid object; the slip clutch is permitted to give so that `the engine may continue to rotate shaft l0 and bevel` gear 86 Yand gear82 without driving the shaft 450. Incase the clutch faces stick, if the propeller :should strike a snag or solid object, then the shear pin 54 will break so that the propeller is notinjured.

the outer clutch member 82 and the threaded collar 92 and that the plug 78' serves wholly to enclose the spring '76 within the housing formed bythe inner clutch member and concentrically It will also be appreciated that the rear end of the bearingsleeve 44 likewise forms a substantially sealed joint aboutthe open end of the collar 92 and that this same bearing is provided with an oil channel 94 which may feed lubricant contained within the chamber 30 to the spiral lubricant feed 62 on'the front end of the shaft.

It will be furtherappreciated that Vby reason of the,Y construction of the gear case head 36 and the manner in which it provides a bearing for the sleeve 44 at the front end of the shaft, a', very convenient and practical mounting of the propeller shaft 50 is provided while at the Asame time by mounting this head 36 in the removable manner as indicated, provision is given for the assembly and removal of the slip clutch and its shaft directly from the housing 2.

Those features of the housing 2 concernedfwithy the formation ofthe water circulating passages and .particularly withreference to ytheir location in respect to the blades ofthe propeller are not herein described since they form the subject matter of other patents and applications filed by me and by I-Iarry L. Johnson and me jointly.

Having thus described my invention, what I claim` as new and desire to secure by Letters Patent is: f

1. yThe combination with the submersible housing of an outboard motor and a propeller drive therefor', including a substantially vertically disposed power shaft and aV propeller shaft angularly disposed therewith, a bevel-gear on said substantially vertically disposed shaft, a rst clutch member on said propeller carrying shaft and, a. second clutch member cooperating with said'first clutch member and provided with bevel gear teeth and meshing with the teeth of the first mentioned gear and a spring urging said clutch members normally into clutching engagement, said spring encircling the propeller drive shaft and being housed within the first clutch member. Y

2; In a device of the class described, the come" bination with a submersible housing having a frontal opening, a gear case headdetachably closing said opening and `having a bore, a tubular bearingY inl said bore, a propeller drive shaft carried by said bearing, a registering bearing car-f ried by Vthe rear end of said housing and in which said propeller drive shaft is mounted, a frustreconical clutch member slidabl'y suppliedfon said propeller carrying shaft and provided rwith a recessed portion about said shaft, a spring coiled about said shaft and seated vin said recessed portion, a collar pinned to said'shaft 'enclosingvsaid recessed portion, a second frustro-conical clutch member concentrically surrounding said first clutch member and provided with-an exterior thread, a collar threaded upon the thread of said outer clutch member and having aflange encircling the propeller carrying drivey shaft, a bevelv gear on said Vouter clutchy member and meshing with a second bevel gear and a substan tially vertical drive shaft rigidly carrying said second bevel gear and Va propeller on' the rear end of said propeller carrying shaft,v 'v

3. In a device of the class described, the com-1 bination with a housing rhaving a substantially vertically' extending Ymotor driven shaft provided with a bevel gear on its'lower end, the lower por-V tion of said housing having transversely disposed bores-at its front andrear end a gear case head detachably mounted on saidhousing so as to close said front opening, a tubular bearing in said gear case head, a screw plug closingthe front of said gear casel head; a propeller carrying drive shaft mounted in the bearings of said gear casehead and said housing, a slip clutch having a part slidable with respect to said shaft and a part having a gear connection with the bevel gear on said motor drivenr shaft and a spring for normally keeping said parts in clutched connection, a propelleronthe rear end of said propeller carrying shaft, a spirallyV arranged lubricant groove on the forward end of saidrshaft andan y oil feed channel at the rear end of saidbearing 140 carried by the gear case head adapted to feed oil to said spiral groove. j

l4. A shock absorbing 'device for the propeller drive of an outboard motor comprising in cornbination a submersible housing, a motor driven 145 shaft mounted therein, a propeller carrying shaft mounted` therein, a propeller' on said shaft; a shear pin rigidly connecting said propellerj tor said shaft and a slip clutchfforming a part .ofl a driving train between said propeller' lcarryingh l5() shaft mounted in said bearing and a slip clutch mounted on said shaft and having a driving connection with the bevel gear on said motor driven shaft, said slip clutch being arranged in line with the opening formed by said gear case head and made smaller than said gear case head whereby to be removable through said opening .when

said gear case head is removed, and a propeller carried on the rear end of said propeller carrying shaft. n

` LOUIS JAMES JOHNSON. 

